MySQL 内部连接别名问题

Question

我正在尝试编写一个 sql 连接，但我遇到了一个不唯一的错误：

SELECT matches.match_id, 
       teamsh.team_name  AS "homeTeam", 
       teamsh.team_id    AS "homeID", 
       teamsa.team_name  AS "awayTeam", 
       teamsa.team_id    AS "awayID", 
       competition.NAME, 
       competition.competition_id, 
       teamsh.stadium, 
       matches.date, 
       teamsh.name_short AS "homeTeamShort", 
       teamsa.name_short AS "awayTeamShort", 
       teamsh.pysioid    AS "pysioIDh", 
       teamsa.pysioid    AS "pysioIDa" 
FROM   matches, 
       teams teamsh, 
       teams teamsa, 
       competition

INNER JOIN
teamsh ON matches.home_team_id = teamh.team_id,
teamsa ON matches.away_team_id = teama.team_id,
competition ON matches.competition_id = competition.competition_id 

WHERE  match_id = 22268

1066 - 不唯一 table/alias：'teamsh'.

我知道我很接近，但别名打败了我。

提前谢谢你，

铝

Answer 1

您将旧式联接与正确的联接语法混合使用：

SELECT matches.match_id, 
       teamsh.team_name  AS "homeTeam", 
       teamsh.team_id    AS "homeID", 
       teamsa.team_name  AS "awayTeam", 
       teamsa.team_id    AS "awayID", 
       competition.NAME, 
       competition.competition_id, 
       teamsh.stadium, 
       matches.date, 
       teamsh.name_short AS "homeTeamShort", 
       teamsa.name_short AS "awayTeamShort", 
       teamsh.pysioid    AS "pysioIDh", 
       teamsa.pysioid    AS "pysioIDa" 
FROM   matches
INNER JOIN
teams AS teamsh ON matches.home_team_id = teamsh.team_id
INNER JOIN 
teams AS teamsa ON matches.away_team_id = teamsa.team_id
INNER JOIN
competition ON matches.competition_id = competition.competition_id 
WHERE  match_id = 22268

您收到错误消息是因为 teamsh 和 teamsa 被多次用作 table names/aliases。

Answer 2

问题出在您的 FROM 子句中。它应该是这样的：

FROM  matches
INNER JOIN
teams teamsh ON matches.home_team_id = teamh.team_id
INNER JOIN
teams teamsa ON matches.away_team_id = teama.team_id
INNER JOIN
competition ON matches.competition_id = competition.competition_id

MySQL 内部连接别名问题

MySQL inner join alias issue

mysql

alias

join

1066 - 不唯一 table/alias：'teamsh'.